A brake control device for a motorcycle is known wherein a front-rear interlocking brake system allows a front-wheel brake as well as a rear-wheel brake to be actuated in an interlocking manner by only operating a brake pedal. For example, JP-A No. H11-5580 discloses a braking device for a motorcycle in which front and rear wheels can be braked by operation of either a brake lever and a brake pedal. When the brake lever is operated, the distribution of a braking force to the front wheel is set to be larger than that to the rear wheel. When the brake pedal is mildly operated, the distribution of a braking force to the rear wheel is set to be larger than that to the front wheel.
In recent years, in the front-rear interlocking brake system an anti-lock brake system (ABS) control is available for preventing the front and rear wheels from being locked, by reducing brake hydraulic pressures to be supplied to a front-wheel brake and a rear-wheel brake. See, for example, JP-A No. 2000-272572.
In the driving of motorcycles placed in the category of so-called super sports bikes, the attitude of a vehicle body may be controlled by adjusting braking force applied to a rear wheel mainly with a brake pedal. Therefore, in the stroke range of the brake pedal for controlling the attitude, a front-wheel brake might be preferably not applied too hard. For this reason, since front-wheel brake caliper pressure is set to start to work after pedal input hydraulic pressure (oil pressure) has reached a predetermined high hydraulic pressure, the rear-wheel brake is actually actuated alone in the stroke range of the brake pedal for controlling the attitude, with control performance equal to normal rear-wheel braking.
However, in the case where the front-wheel and rear-wheel interlocking brake system with the ABS control is employed, there is a possibility that, once the rear wheel is locked and the ABS control becomes active, no larger braking force can be applied to the rear wheel even when the brake pedal is strongly operated. Therefore, in order to generate a further braking force by only operating the brake pedal, an application of a braking force to the front wheel which is not locked is necessary. Thus, the brake pedal might have to be pushed with a force to exceed the threshold set to a high hydraulic pressure so as to permit control of the vehicle body attitude.